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The mystery that data of open quotation of hard disk of analytic high capacity r
From;  Author:Stand originally

Initial stage develops in hard disk technology, the packing density that promotes disk is very easy, right now namely larger odd dish size. However, at present hard disk manufacturer encountered difficult problem however. Dish piece be alloy is made in aluminium or of vitreous basic level exceed coating of thin magnetism of flowing apparently ordinal coating, protection coating and exterior lubricant to wait form. Dish piece with 4200RPM ~ the rotate speed of 15000RPM turns, magnetic head does the linear exercise of move back and forth, and can be in dish an any positions that go up read take or keep information. Microcosmic in light of, dish a thin magnetism coating that go up be by the amount numerous, the magnetism grain composition with very petty bulk. Many magnetism grain (about 100 or so) the information ——0 that comprises unit of a record to record 1bit or 1.

The requirement that records equipment to magnetism now is bulk smaller and smaller, the size is larger and larger, namely area density is higher and higher, such magnetism grain are less and less also of course. It is 20 Gbit when area density for instance when, magnetism grain diameter is 13 accept rice about, and when achieving 100 Gbit, the diameter narrowed 9.5 accept rice. When the volume when magnetism grain is too minor, the factor that can affect its magnetic hysteresis is exterior magnetic field not just, the magnetic hysteresis that trifling quantity of heat can affect magnetism grain (the heat energy below for example room temperature) , the data that brings about magnetism to record equipment to go up thereby is missing, this kind of phenomenon is “ exceeds paramagnetic effect ” .

Because the magnetic circuit direction of magnetism unit produced the about-face of 90° , the tectonic affirmation that keeps magnetic head should undertake altering accordingly, in order to produce magnetization direction is perpendicular at dish an exterior magnetic field. The magnetic head design of perpendicular record is very clever: Its signal extremely very narrow, flux density is higher, enough makes through the magnetism below it unit happening magnetic circuit inverts. And return extremely very wide, flux density is inferior, because this magnetism unit below it is quite safe. Of course, medium must perform an operation a bit more —— not only magnetism layer (strong record layer) meeting thickening, its issue addition soft magnetism ground floor to still conduce to improvement writing fashionable stability.

Restore to operate to open quotation data and character, the structural change of magnetic head is enormous challenge undoubtedly. Change directly before the operation of magnetic head becomes more difficult, need a few mechanical equipment to undertake assisting however. Ministry of flying guest research and development passes hard disk of pair of jotter of rare nimble Momentus 5400.3, rare nimble hard disk of 7200.1 table machine and Toshiba MK8007GAH 1.8 inch the research of miniature hard disk, had solved thoroughly cannot change magnetic head and the question with difficult fixed position, also pass its at the same time because perpendicular magnetization hard disk increased soft magnetism,special method avoids rock-bottom and the magnetic head sensitivity that bring about. The success of this technology research and development means flying guest to be in the lead position that a few years the lieutenant general will continue to maintain a technology to go up henceforth, ensure taller open quotation data restores to be led successfully.
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